Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Innovation in spectroscopy could improve greenhouse gas detection

16.05.2013
Detecting greenhouse gases in the atmosphere could soon become far easier with the help of an innovative technique* developed by a team at the National Institute of Standards and Technology (NIST), where scientists have overcome an issue preventing the effective use of lasers to rapidly scan samples.

The team, which recently published its findings in the journal Nature Photonics, says the technique also could work for other jobs that require gas detection, including the search for hidden explosives and monitoring chemical processes in industry and the environment.


Fast, accurate spectroscopy scans of the atmosphere across a wide range of light frequencies could improve the performance of greenhouse gas measurement devices. This artist's conception compares current technology, which functions slowly and unevenly, with the NIST team's improvement, which changes the scanning laser's frequency evenly and more than 1,000 times faster, permitting full-spectrum scans within a few milliseconds.

Credit: Talbott, Gerskovic/NIST

Searching for faint whiffs of an unusual gas mixed in the air is called "trace gas sensing." By far, the most common method is spectroscopy—identifying gas molecules by the unique set of frequencies of light that each absorbs. The telltale pattern of dark lines in a spectrum indicates which gases are present in the mix. Accurately measuring the concentrations of relatively low-concentration gases, however, requires a lot of light, generated by a laser that can be tuned to different colors. Until now, tuning a laser to shine in a wide enough range of colors typically has required a mechanical device to change the frequency, but all the available methods adjust the laser too slowly to obtain meaningful snapshots of the turbulent atmosphere.

"One of the major goals in climate science is to combine a wide variety of high-accuracy atmospheric measurements, including ground-based, aircraft and satellite missions, in order to fully understand the carbon cycle," says the research team's David Long, a scientist in NIST's Chemical Sciences Division. "The technology we've developed is general enough to be applicable for each of these platforms. The high speed of the technique allows for very accurate measurements of atmospheric gases at rates which are faster than atmospheric changes in temperature and pressure due to turbulence."

The team found a solution using electronics that permit fast and discrete changes in frequency. The components—called an electro-optic modulator and an optical resonator—work together to alter the laser so that its light shines in a number of different frequencies, and then to filter these frequencies so that the laser only shines in one color at any given instant. The new method allows a wide range of different frequencies to pass through a gas sample in a few milliseconds or less, with the added benefit of providing a clearer and more accurate resulting spectrum than the previous "slow scan" methods could.

Long says that the Nature Photonics paper details the use of the technique in a controlled laboratory environment using a small sample chamber for ground-based measurements, but that the team has submitted other papers with data indicating the technique also could work at great distances—potentially allowing a scanner to be mounted on a vehicle, an aircraft or a satellite. The team also has applied for a patent on its work, he says.

*G.-W. Truong, K.O. Douglass, S.E. Maxwell, R.D. van Zee, D.F. Plusquellic, J.T. Hodges and D.A. Long. Frequency-agile, rapid scanning spectroscopy. Nature Photonics, DOI: 10.1038/NPHOTON.2013.98, April 28, 2013.

Chad Boutin | EurekAlert!
Further information:
http://www.nist.gov

More articles from Earth Sciences:

nachricht Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft

nachricht How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

Im Focus: Optoelectronic Inline Measurement – Accurate to the Nanometer

Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.

New Manufacturing Technologies for New Products

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

A new technique isolates neuronal activity during memory consolidation

22.06.2017 | Life Sciences

Plant inspiration could lead to flexible electronics

22.06.2017 | Materials Sciences

A rhodium-based catalyst for making organosilicon using less precious metal

22.06.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>